The proton magnetic resonance spectra of N-nitroso derivatives of sarcosine, proline and iminodiacetic acid

1971 ◽  
Vol 24 (9) ◽  
pp. 1949 ◽  
Author(s):  
FHC Stewart
Keyword(s):  
Magnetic Resonance ◽  
Long Range ◽  
Proton Magnetic Resonance ◽  
Iminodiacetic Acid ◽  
Conformational Isomerism ◽  
Nitroso Group ◽  
Restricted Rotation ◽  
Derivatives Of ◽  
Shielding Effects ◽  
Magnetic Resonance Spectra

The proton magnetic resonance spectra of various N-nitroso derivatives of sarcosine, L-proline, and iminodiacetic acid, including some protected dipeptides, have been obtained. Magnetic non-equivalence and conformational isomerism arising from restricted rotation of the nitroso group are discussed in relation to the reported behaviour of other nitrosamines. Long-range shielding effects on protons at a considerable distance from the anisotropic nitrosamino centre were readily detected with these compounds.

Proton magnetic resonance spectra of some β-methylstyrenes, β,β-dimethylstyrenes, and α-methylstilbenes; and a discussion of long-range shieldingand coupling effects in these and related systems

1965 ◽  
Vol 18 (11) ◽  
pp. 1759 ◽  
Author(s):  
H Rottendorf ◽  
S Sternhell ◽  
JR Wilmshurst
Keyword(s):  
Magnetic Resonance ◽  
Long Range ◽  
Proton Magnetic Resonance ◽  
Coupling Constants ◽  
Coupling Effects ◽  
Styrene Derivatives ◽  
Shielding Effects ◽  
Magnetic Resonance Spectra

The preparation of some new β,β-dimethylstyrenes and α-methylstilbenes is described and their p.m.r. spectra are reported. The long-range shielding effects in β,β-dimethylstyrenes and other styrene derivatives are discussed. The differences between the cisoid and transoid allylic coupling constants in β,β-dimethylstyrenes are much smaller than the corresponding differences in simple propenes. No appreciable (J ≥ 0.3 c/s) coupling between the non-equivalent methyl protons in β,β-dimethylstyrenes has been observed. Long-range coupling in the compounds investigated appears to be independent of ring substitution. Some general features of allylic coupling are discussed.

scholarly journals Long-range spin–spin coupling in N-methyl 2-carbomethoxy-4,6-dinitroaniline

1970 ◽  
Vol 48 (6) ◽  
pp. 934-941 ◽  
Author(s):  
J. A. McCubbin ◽  
R. Y. Moir ◽  
G. A. Neville
Keyword(s):  
Magnetic Resonance ◽  
Carbonyl Group ◽  
Long Range ◽  
Proton Magnetic Resonance ◽  
Chemical Shifts ◽  
Relative Magnitude ◽  
Spin Coupling ◽  
Spin Spin Coupling ◽  
Derivatives Of ◽  
Shielding Effects

Long-range coupling [Formula: see text] between the amino proton and the C-5 ring proton of N-methyl 2-carbomethoxy-4,6-dinitroaniline (1) was established unequivocally by comparison of the proton magnetic resonance spectra of the 3-d and 5-d analogs of 1 together with the N-deutero derivatives of the above compounds. Deuterium decoupling experiments indicated that meta-deuterium coupling was of the order of band resolution (< 0.2 Hz). Elucidation of the source of long-range coupling with the amino proton enabled the chemical shifts of the aromatic protons to be assigned. The relative magnitude of these chemical shifts is discussed in terms of the shielding effects operative in the predominant conformer in which the amino hydrogen is intramolecularly hydrogen bonded to the oxygen of the ester carbonyl group.

ChemInform Abstract: PROTON MAGNETIC RESONANCE SPECTRA OF ANIONIC Σ-COMPLEXES OF TRINITROBENZENE WITH CYCLOPENTADIENYL AND INDENYL DERIVATIVES OF TIN

1976 ◽  
Vol 7 (50) ◽  
pp. no-no
Author(s):  
YU. A. USTYNYUK ◽  
G. A. ARTAMKINA ◽  
YU. N. LUZIKOV ◽  
YU. K. GRISHIN ◽  
A. A. AZIZOV ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Derivatives Of ◽  
Magnetic Resonance Spectra

Proton magnetic resonance spectra of some benzo[b]thiophens. An investigation of substituent effects in a heteroaromatic system

1968 ◽  
Vol 21 (7) ◽  
pp. 1853 ◽  
Author(s):  
B Caddy ◽  
M Martin-Smith ◽  
RK Norris ◽  
ST Reid ◽  
S Sternhell
Keyword(s):  
Magnetic Resonance ◽  
Long Range ◽  
Proton Magnetic Resonance ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Spin Coupling ◽  
Heteroaromatic System ◽  
Spin Spin Coupling ◽  
Magnetic Resonance Spectra

N.m.r. data for 19 5-substituted and 13 polysubstituted benzo[b]thiophens are tabulated. The influence of the substituents at C5 on the chemical shifts of H4 and H6 is discussed. Long-range interproton spin-spin coupling between H3 and H7, and between H2 and H6, is general in benzo[b]thiophens. The vicinal coupling J6,7 in 5-substituted benzo[b]thiophens varies directly and linearly with the electronegativity of the substituents at C5.

Complexes of uranyl β-diketonates with sulphoxides

1973 ◽  
Vol 26 (1) ◽  
pp. 85 ◽  
Author(s):  
MS Subramanian ◽  
SA Pai ◽  
VK Manchanda
Keyword(s):  
Magnetic Resonance ◽  
Steric Hindrance ◽  
Proton Magnetic Resonance ◽  
Free Rotation ◽  
Sulphur Atom ◽  
Neutral Donor ◽  
Restricted Rotation ◽  
Metal Bond ◽  
Methylene Group ◽  
Magnetic Resonance Spectra

The proton magnetic resonance spectra of the synergistic complexes of uranyl β-diketonates with dihexyl sulphoxide as the neutral donor give a multiplet consisting of eight lines for the terminal methylene group protons adjacent to the sulphur atom of the sulphoxide and a triplet for the β-methylene protons. This conforms to an ABX2 pattern arising as a result of nonequivalence of the two protons of the terminal methylene group as a result of steric hindrance to free rotation about the C-S bond. The presence of such restricted rotation has been adduced as evidence for a direct donor-metal bond.

The proton magnetic resonance spectra of phenol in the absence of intermolecular proton exchange

1976 ◽  
Vol 54 (23) ◽  
pp. 3666-3671 ◽  
Author(s):  
Ted Schaefer ◽  
J. B. Rowbotham ◽  
Kalvin Chum
Keyword(s):  
Magnetic Resonance ◽  
Long Range ◽  
Proton Magnetic Resonance ◽  
Proton Exchange ◽  
Associated Species ◽  
Hydroxyl Protons ◽  
Model Support ◽  
Magnetic Resonance Spectra

The proton magnetic resonance spectra in the absence of intermolecular proton exchange for 0.27, 0.59, and 0.79 M solutions of phenol in CCl4 are analyzed. The long-range coupling over five bonds between the hydroxyl and ring protons is estimated as 0.33 Hz in the monomer and as 0.20 Hz in the trimer of a monomer–trimer model. Support for the decrease in the coupling on trimerization is found in CNDO/2 and INDO MO FPT calculations. The long-range coupling over six bonds is unobservable, consistent with conformations of the trimer in which the phenol molecules remain planar. Water catalyzes the intermolecular proton exchange and, in its absence, the transfer of hydroxyl protons from molecule to molecule within the associated species is inefficient.

The analysis of the proton magnetic resonance spectra of heteroaromatic systems. V. Diazanaphthalenes

1965 ◽  
Vol 18 (5) ◽  
pp. 707 ◽  
Author(s):  
PJ Black ◽  
ML Heffernan
Keyword(s):  
Carbon Tetrachloride ◽  
Magnetic Resonance ◽  
Long Range ◽  
Iterative Procedure ◽  
Proton Magnetic Resonance ◽  
Chemical Shifts ◽  
Direct Calculation ◽  
Coupling Constants ◽  
Dilute Solutions ◽  
Magnetic Resonance Spectra

The proton magnetic resonance spectra of the four isomeric diazanaphthalenes, quinoxaline, phthalazine, quinazoline, and cinnoline, all as dilute solutions in carbon tetrachloride and acetone, have been investigated at 100 Mc/s. The chemical shifts and coupling constants have been obtained by direct calculation or, where appropriate, by an iterative procedure. Long-range coupling constants between protons separated by five and six bonds have been observed.

The infrared and proton magnetic resonance spectra of hydroxyl ion and water in a potassium nitrate-sodium nitrite melt

1971 ◽  
Vol 24 (11) ◽  
pp. 2213 ◽  
Author(s):  
AG Turnbull
Keyword(s):  
Hydrogen Bonding ◽  
Magnetic Resonance ◽  
Sodium Nitrite ◽  
Proton Magnetic Resonance ◽  
Potassium Nitrate ◽  
Low Concentration ◽  
Restricted Rotation ◽  
Hydroxyl Ion ◽  
Magnetic Resonance Spectra

The infrared and proton magnetic resonance spectra are reported for OH- and H2O at low concentration (<2 mol %) in a KNO3-NaNO2 melt at 150�C. The spectra indicate the absence of hydrogen bonding and the presence of restricted rotation and translation for OH- but the presence of strong complexing to cations and anions for H2O.

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